Almost 40% of Veterans using VA are obese and have associated debilitating chronic health conditions. Populations at particular risk include women, Veterans from racial or ethnic minority groups, and rural dwelling Veterans. VA developed the MOVE! weight management program to address obesity but 50% of Veterans who enroll in MOVE! attend only one session and recent evaluations suggest modest weight loss and potential gender and racial/ethnic disparities in outcomes. MOVE! was implemented with flexibility in program design, with some standard elements and other elements determined locally. For the most part, little is known about how well these local variations in specific program elements meet the needs of local MOVE! populations and assist Veterans in adopting healthier lifestyles and managing their weight. Growing evidence suggesting the importance of environmental attributes (e.g., healthy food availability and prices, walkability, access to recreational places such as parks) in obesity- related behaviors points to a promising new direction for investigation: the interplay between weight management interventions and the environment in influencing people's ability to adopt and sustain healthy lifestyles. Drawing on an innovative conceptual model that incorporates aspects of a social-ecological model and microeconomic theory of the demand for and production of health, the goal of the proposed research is to understand environmental contributions to MOVE! engagement and outcomes and how best to assist Veterans in adopting lifestyle change through MOVE! by taking into account the residential environment. In a nationwide sample of overweight and obese Veterans, specific aims are (1) Determine the extent to which local MOVE! elements are aligned with Veterans' residential environment attributes; (2) Determine the extent to which specific MOVE! elements promote engagement for Veterans living in environments with or without facilitating attributes; (3) Determine the extent t which attributes of the residential environment and specific MOVE! elements interact to help MOVE! participants lose weight at 6 months and maintain weight loss at 18 months; and (4) Determine whether African American, Hispanic, female, and rural Veterans are different from their Non-Hispanic White, male, and urban-dwelling counterparts in regard to the environment- MOVE! relationships and impacts on weight loss examined in Aims 2 and 3. To address these aims, the proposed research will use a retrospective design in which MOVE! program data on specific elements available at each facility and information on Veterans' MOVE! engagement, health including body weight and other measures, and healthcare utilization are linked to public and proprietary data characterizing Veterans' residential environments. Analyses will employ a matched control group derived through propensity score analysis and panel data statistical models that are robust to a broad class of potential sources of bias and reverse causality. Veteran populations at highest risk for obesity and associated morbidity and for exposure to environments with fewer salutary attributes--women, racial and ethnic minorities, and those living in rural areas--will be a key focus of this research.